Constant current and constant voltage regulating circuit for common-gate or common-base transistor devices

Abstract

A circuit for maintaining a constant voltage across and constant current through an RF cavity includes a RF cavity comprising a common-gate or common-base transistor associated with a current control circuit maintains a constant current flowing through the RF cavity. The current control circuit has a current control BJT associated with the RF cavity and a resistor between the emitter of the current control BJT and the negative source voltage of the RF cavity. The current control BJT and resistor operate as a current source or sink as necessary to maintain a constant current flow through said RF cavity. A constant voltage regulation portion of the circuit maintains a constant voltage across the RF cavity and includes a zener reference diode and a voltage regulation BJT. The zener reference diode has an associated isolation operational amplifier circuit for isolating the zener reference diode from current fluctuations at the source while permitting the zener reference diode to respond to voltage difference changes across the RF cavity. The zener reference diode and voltage regulation BJT control voltage applied to the RF cavity. The current control circuit and constant voltage regulation circuit automatically maintain a constant current passing through and constant voltage difference across the RF cavity.

We claim: 
     
       1. A method for maintaining a constant voltage across and constant current through an RF cavity, comprising the steps of: generating a voltage across and a current through said RF cavity with a common-gate transistor having a source and a drain;   automatically maintaining a constant current flowing through said RF cavity using a current control circuit associated with said source to operate as a current source or sink as necessary to maintain a constant current flow through said RF cavity;   automatically maintaining a constant voltage across said RF cavity using a constant voltage regulation circuit comprising a zener reference diode and a voltage regulation BJT; and   isolating said zener reference diode from current fluctuations at said source while permitting said zener reference diode to respond to voltage difference changes across said RF cavity.   
     
     
       2. A circuit for maintaining a constant voltage across and constant current through an RF cavity, comprising: a common-gate transistor in said RF cavity, said common-gate transistor having a source and a drain;   a current control circuit associated with said source to maintain a constant current flowing through said RF cavity, said current control circuit comprising a current control BJT associated with said source and a resistor associated between the emitter of said current control BJT and a source voltage, said current control BJT and said resistor associated to operate as a current source or sink as necessary to maintain a constant current flow through said RF cavity;   a constant voltage regulation circuit for maintaining a constant voltage across said RF cavity and comprising a zener reference diode and a voltage regulation BJT, said zener reference diode having an associated isolation operational amplifier circuit for isolating said zener reference diode from current fluctuations at said source while permitting said zener reference diode to respond to voltage difference changes across said RF cavity, said zener reference diode further associated with the base of said voltage regulation BJT for controlling voltage applied to said drain to maintain a constant voltage across said RF cavity, said constant voltage regulation circuit further comprising a constant voltage source applied to the collector of said voltage regulation BJT and a minimum current flow resistor associated between the cathode of said zener reference diode and said constant voltage source and between the base of said voltage regulation BJT and said constant voltage source; and   said current control circuit and said constant voltage regulation circuit associated to automatically maintain a constant current passing through and constant voltage difference across said RF cavity.   
     
     
       3. A method for maintaining a constant voltage across and constant current through a regulated transistor device, comprising the steps of: generating a voltage across and current through said transistor device comprising a common-gate transistor;   maintaining a constant current flowing through said transistor device by operating current control means as a current source or sink as necessary to maintain a constant current flow through said transistor device;   maintaining a constant voltage across said transistor device using constant voltage regulation means comprising a zener reference diode and a voltage regulation transistor for responding to voltage difference changes across said transistor device; and   automatically maintaining a constant current passing through and constant voltage difference across said transistor device by associating said current control means with said constant voltage regulation means.   
     
     
       4. A circuit for maintaining a constant voltage across and constant current through a regulated transistor device, comprising: said transistor device comprising a common-gate transistor;   current control means for maintaining a constant current flowing through said transistor device, said current control means associated with said transistor device to operate as a current source or sink as necessary to maintain a constant current flow through said transistor device;   constant voltage regulation means for maintaining a constant voltage across said transistor device and comprising a zener reference diode and a voltage regulation transistor for responding to voltage difference changes across said transistor device;   said current control means and said constant voltage regulation means associated to automatically maintain a constant current passing through and constant voltage difference across said transistor device.   
     
     
       5. A method for maintaining a constant voltage across and constant current through a power amplifier circuit having a power amplifier transistor comprising the steps of: generating a voltage and a current using said power amplifier transistor comprising a common-gate transistor having a source and a drain;   maintaining a constant current flowing through said power amplifier transistor using current control circuit associated with said source, by associating a current control BJT with said source and a resistor between the emitter of said current control BJT and a source voltage, and further by operating said current control BJT and said resistor as a current source or sink as necessary to maintain a constant current flow through said power amplifier transistor;   maintaining a constant voltage across said power amplifier transistor using a constant voltage regulation circuit comprising a zener reference diode and a voltage regulation BJT so that said zener reference diode associates with the base of said voltage regulation BJT for controlling voltage applied to said drain to maintain a constant voltage across said power amplifier transistor, said constant voltage regulation circuit further comprising a constant voltage source applied to the collector of said voltage regulation BJT and a minimum current flow resistor associated between the cathode of said zener reference diode and said constant voltage source and between the base of said voltage regulation BJT and said constant voltage source; and   automatically maintaining a constant current passing through and constant voltage difference across said power amplifier transistor by using said current control means in association with said constant voltage regulation circuit.   
     
     
       6. A power amplifier circuit for maintaining a constant voltage across and constant current through a power amplifier transistor comprising: said power amplifier transistor comprising a common-gate transistor having a source and a drain;   a current control circuit associated with said source to maintain a constant current flowing through said power amplifier transistor, said current control circuit comprising a current control BJT associated with said source and a resistor associated between the emitter of said current control BJT and a source voltage, said current control BJT and said resistor associated to operate as a current source of sink as necessary to maintain a constant current flow through said power amplifier transistor;   a constant voltage regulation circuit for maintaining a constant voltage across said power amplifier transistor and comprising a zener reference diode and a voltage regulation BJT, said zener reference diode associated with the base of said voltage regulation BJT for controlling voltage applied to said drain to maintain a constant voltage across said power amplifier transistor, said constant voltage regulation circuit further comprising a constant voltage source applied to the collector of said voltage regulation BJT and a minimum current flow resistor associated between the cathode of said zener reference diode and said constant voltage source and between the base of said voltage regulation BJT and said constant voltage source; and   said current control circuit and said constant voltage regulation circuit associated to automatically maintain a constant current passing through and constant voltage difference across said power amplifier transistor.   
     
     
       7. A method for maintaining a constant voltage across and constant current through a low-noise amplifier circuit using a low-noise amplifier transistor, comprising the steps of: generating a voltage and current using said low-noise amplifier transistor comprising a common-base transistor having an emitter and a collector;   maintaining a constant current flowing through said low-noise amplifier transistor using a current control circuit associated with said emitter and comprising a current control transistor associated with said emitter and a resistor associated between said current control transistor and a source voltage so as to operate as a current source or sink as necessary to maintain a constant current flow through said low-noise amplifier transistor;   maintaining a constant voltage across said low-noise amplifier transistor using a constant voltage regulation circuit comprising a zener reference diode and a voltage regulation transistor while isolating said zener reference diode from current fluctuations at said emitter and permitting said zener reference diode to respond to voltage difference changes across said low-noise amplifier transistor, and further associating said zener reference diode with said voltage regulation transistor for controlling voltage applied to said collector to maintain a constant voltage across said low-noise amplifier transistor; and   associating said current control circuit and said constant voltage regulation circuit further to automatically maintain a constant current passing through and constant voltage difference across said low-noise amplifier transistor.   
     
     
       8. A low-noise amplifier circuit for maintaining a constant voltage across and constant current through a low-noise amplifier transistor comprising: said low-noise amplifier transistor comprising a common-base transistor having an emitter and a collector;   a current control circuit associated with said emitter to maintain a constant current flowing through said low-noise amplifier transistor, said current control circuit comprising a current control transistor associated with said emitter and a resistor associated between said current control transistor and a source voltage, said current control transistor and said resistor associated to operate as a current source of sink as necessary to maintain a constant current flow through said low-noise amplifier transistor;   a constant voltage regulation circuit for maintaining a constant voltage across said low-noise amplifier transistor and comprising a zener reference diode and a voltage regulation transistor, said zener reference diode isolated from current fluctuations at said emitter while permitting said zener reference diode to respond to voltage difference changes across said low-noise amplifier transistor, said zener reference diode further associated with said voltage regulation transistor for controlling voltage applied to said collector to maintain a constant voltage across said low-noise amplifier transistor, said constant voltage regulation circuit further comprising a constant voltage source applied to said voltage regulation transistor and a minimum current flow resistor associated between the cathode of said zener reference diode and said constant voltage source and between said voltage regulation transistor and said constant voltage source; and   said current control circuit and said constant voltage regulation circuit associated to automatically maintain a constant current passing through and constant voltage difference across said low-noise amplifier transistor.